The invention is concerned with fibre drums having galvanized steel chimes, and in particular such drums which are intended to contain aggressive chemicals as might be expected to corrosively attack the drum, and specifically the steel chime thereof.
The fibre body of the drum, normally formed of multiple convolutely wound paperboard plies, is conventionally protected by a bonded inner liner of corrosive resistent plastic film material such as polyethylene. While such liners effectively protect the interior of the container, there is a continuing problem with regard to providing corrosion protection for the steel chime. The commercial solutions to this problem are considered to be less than adequate.
As one commercial solution to the problem of corrosive attacks, a thin strip of stainless steel is wrapped around the exposed surface of the chime as an overlay prior to the forming of the chime to the container body. However, with such overlays, a potential leakage path exists under the chime and/or between the chime and the overlay. Such leakage may occur if a liquid-containing drum made in this way is stored on its side; similarly, excessive amounts of oxygen and/or water may be transported into the drum by this route. Further, some products are corrosive to stainless steel.
Another current commercial attempt to solve this problem involves the use of a sleeve of polyethylene film bonded at one edge to the drum lining and cuffed to snugly although freely overlie the chime. Such an arrangement will be noted in the patent to Gibbs, Jr. U.S. Pat. No. 2,798,654 issued July 9, 1957. As an alternative method of attaching the film sleeve, the sleeve is crimped under the steel chime by folding it over the end of the tube before the chime is assembled and crimped in place. Such plastic sleeves, loosely overlying the chime, are easily damaged by handling abuse which frequently results in destructive abrasion of the sleeve. Further, difficulties have been encountered in obtaining a continuous bonding or sealing of the loose plastic sleeve to the liner. As the sleeve-to-liner engagement constitutes with such arrangements the only barrier to the corrosive material, any breaching of this barrier will result in an exposure of the entire chime within the sleeve.